Recently I was writing an import in SSIS and needed to use a ASCII 127 as delimiter. I know you can type a custom delimiter into SSIS but ASCII 127 is the delete character. Steve Kass reminded me that SSIS' .dtsx files are just giant XML files and easy to edit. It was as simple as changing this line:
<DTS:Property DTS:Name="ColumnDelimiter" xml:space="preserve">_x007F_</DTS:Property>
007F is the hex code for ASCII 127. Thanks Steve!